What was the focus of your PhD research? Can you explain it to a non-scientific audience?

My focus was about studying ferromagnetic and superconducting materials with the aim of improving magnetic sensors, and functional devices present in our society.

Can you briefly summarize the main findings or contributions of your research? You can give us some examples.

I worked in three different lines: One was to optimize a magnetic sensor based on Planar Hall Effect; The second was to study a magnetic flux concentrator in the micro and nano scale; Finally, the third one is about demonstrating some signatures of Spin-Orbit Coupling in High-Temperature Superconductors (HTS) cuprates.

Why do you think your research is important, and how could it impact your field or society?

The concentrators are very important because we manage to enhance up to 150 times the sensitivity of a magnetic sensor. And The Spin-Orbit coupling in HTS cuprates can lead to a potential application for spintronics.

What was one of the most challenging aspects of your PhD journey, and how did you overcome it?

During the first years when I had difficulties getting good results because everything was new and the projects that I was working on were also new and we did not have so many references. By trying and improving the fabrication process and designs it leads to a good result.

Why did you end up at ICMAB? And what do you think you will miss the most from this institute?

I studied Nanocience and Nanotechnology Master in UAB and I contacted for the first time with my director to make the Maste's Thesis (TFM). The people and the good atmosphere will be missed the most. 

What’s next for you after completing your PhD? Do you have any upcoming projects or goals?

Now I am continuing in ICMAB for several months to finish some projects that we are working on but also, I am looking for a postdoc abroad.

How has completing this PhD changed you, either professionally or personally?

I feel this last year helped me to process all the information and results during the first year which helped me to further understand all the effects and physics related to my work which now I feel like a complete expert on this subject.

What advice would you give to someone just starting their PhD journey?

You need to start calmly without hurrying and progressively start to put more effort into your research but without pressure just because you want to discover and learn new things not because you need results.

Why did you become a scientist? Which have been your role models that inspired you to pursue a PhD?   

I had no models that inspired me exactly, but one friend that was studying Nanoscience and Nanotechnology introduced me into this world and it fascinated me.

Who or what helped you the most during your PhD journey, and is there anyone you'd like to thank?

Yes, many people supported me throughout this journey. First and foremost, my girlfriend Lucía, who was always by my side. I am also deeply grateful to the coworkers I consider friends, including Thomas, Meritxell, Jordi, Alejandro, Huidong, Anton, Karla, Marti, Aiswarya, and many others who helped me with my experiments and shared countless experiences with me over the years. My family, including Ramon, Maria Victoria and Nil, supported me every single day, and I could not have done it without them. Finally, I want to thank my director and supervisors: Anna Palau, Lluís and Narcís, for their guidance and support.

 Aleix Barrera on the day of his thesis at ICMAB garden | ICMAB-CSIC 

 Abstract

This study investigates magnetic metasurfaces composed of thin ferromagnetic films designed for magnetic flux concentration. To quantify magnetic enhancement and performance, various types of magnetic sensors based on anisotropic magnetoresistance were evaluated to optimize their operation within the magnetic flux concentrators. The results demonstrate significant magnetic enhancement potential, strongly influenced by metasurface design parameters such as thickness, size, and shape. Additionally, the study provides evidence of spin-orbit coupling in high-temperature superconductors, specifically YBCO, as revealed through magneto-transport measurements.

Supervisors

• Anna Palau, ICMAB-CSIC, Spain

PhD Committee

• President: José María De Teresa , NANOMIDAS Universidad de Saragossa , Spain
• Secretary: Alberto Pomar, ICMAB, Spain
• Vocal: Rosa Córdoba, ICMOL, Spain